Method and apparatus for converting organic material

ABSTRACT

The present invention relates to a method and apparatus for intensifying the energy content of an organic material by converting the material into hydrocarbons and the resulting product thereof. A method for converting an organic material into hydrocarbon fuels is disclosed. The method comprising the steps of pressurizing said organic material being in a fluid to a pressure above 225 bar, heating said organic material in said fluid to a temperature above 200 C in the presence of a homogeneous catalyst comprising a compound of at least one element of group IA of the periodic table of elements. The disclosed method further comprises the steps of contacting said organic material in said fluid with a heterogeneous catalyst comprising a compound of at least one element of group IVB of the periodic table and/or alpha-alumina assuring that said fluid has initially a pH value of above 7.

The present invention relates to a method and apparatus for intensifyingthe energy content of an organic material by converting the materialinto hydrocarbons and the resulting product thereof.

BACKGROUND

The world's energy demand is increasing, and the fossil fuel sources aredepleted, leading to increasing competition for the available energysources, and thereby hampering economical growth by high energy prices.To overcome this situation renewable energy sources must be brought intoexploitation. The only renewable energy source with sufficient capacityto cover significant parts of the energy demand is biomass conversion.Biomass is efficiently converted into heating and electricity byexisting technologies, but transportation fuels, which accounts for onethird of the total energy consumption, must be available as high energydensity fluids, preferably compatible with fossil fuels like diesel oiland gasoline. Therefore technologies for transforming and intensifyingthe energy content of biomass are required.

At the same time all kinds of waste are produced all over the world fromfactories, households etc., and as a result waste disposal has increasedto an insuperable amount of waste over the last decades. Dumping ofwaste has become an increasingly problem and therefore a cheap effectivedispose of waste has become increasingly more important.

A known method of waste disposal is refuse incineration. But numerouswastes are due to the high water content not suitable for incineration,e.g. sewage sludge and industrial waste water treatment residues.Incineration of such wastes require additional energy input, i.e. theoverall process energy is negative.

In view of this new methods have been developed for treatment of suchwastes. However these known methods are still very limited in regards tothe kind of waste, which may be treated in the same apparatus and inregards to how much of the converted waste which is turned intorecyclable products. Additionally, the energy of the organic material,which is converted into recyclable products are still very low comparedto the amount of energy added to the method. Therefore in order to makeconversion of organic material commercial interesting there is still aneed of a more energy effective process.

Furthermore, known methods have shown that char and soot deposit insidethe apparatus in such an amount that regular cleaning of the apparatusis needed. Such cleaning operations are time consuming and thereforeexpensive.

Corrosion of the materials used for making apparatus for the convertingof organic material has in known methods been such a problem that thematerials for these components had to be chosen in a more expensivegroup of materials. This problem of corrosion has increased the cost ofthe apparatus for the converting and therefore decreased the incentivefor using converting of waste instead of refuse incineration.

SUMMARY OF THE INVENTION

An objective of the present invention is to provide an improved methodand an improved apparatus for converting organic material, such aswaste, sludge, biomass etc., into recyclable products, such ashydrocarbon fuel, which method at least partly overcome or at leastmitigate the aforementioned problems and disadvantages.

Another objective of the present invention is to provide an improvedrecyclable product from the conversion of organic material, whichimproved product is reusable as some kind of energy. These objectivesand several others objectives, which will become evident below areobtained by a first aspect of the present invention by providing amethod for converting an organic material into hydrocarbon fuels,comprising the steps of:

-   -   pressurizing said organic material in a fluid to a pressure        above 225 bar, and    -   heating said organic material in said fluid to a temperature        above 200 C. in the presence of a homogeneous catalyst        comprising a compound of at least one element of group IA of the        periodic table of elements,        wherein the method further comprises the steps of:    -   contacting said organic material in said fluid with a        heterogeneous catalyst comprising a compound of at least one        element of group IVB of the periodic table and/or alpha-alumina,        and    -   adjusting said fluid to a pH value of above 7.

An improved method for converting organic material into recyclableproducts is hereby obtained. By contacting the organic material with aheterogeneous catalyst comprising a compound of at least one element ofgroup IVB of the periodic table and/or alpha-alumina, the catalyst maybe reused and a continuously converting of organic material is possible.Thereby the amount of catalyst spent for converting one amount oforganic material is decreased whereby the cost for converting thematerial is considerable decreased. Additionally, the process time hasbeen decreased considerably due to the fact that dividing the catalystprocess into two separate processes increases the velocity ofconversion.

Furthermore, by adjusting the fluid to above 7 the corrosion of thematerials used for the involved components in the apparatus isconsiderably decreased. The corrosion of these materials has decreasedto such an amount that cheap standard materials may be used for theconstruction of the apparatus.

According to another aspect of the present invention the method maycomprise the step of maintaining the pH value of said fluid containingsaid organic material in the range 7-14, such as 7-12 and preferably inthe range 7-10 such as in the range 7-9.5. It is hereby obtained thatwhen converting the organic material into hydrocarbon fuel the corrosionof the materials used for the involved components of the apparatus issubstantial decreased to at least an insignificant amount of corrosion.

Furthermore, according to an aspect of the present invention the methodmay comprise the step of pre-treating the organic material at a pressureof 4-15 bar at the temperature of 100-170 C for a period of 0.5-2 hours.By pre-treating the organic material at this pressure, the organicmaterial is pre-converted whereby the subsequent conversion may beperformed more quickly than without the pre-treatment.

Subsequently, the pre-treating step may according to another aspect ofthe invention comprise a step of size reducing of the material such as acutting, grinding, milling, or sieving step or a combination thereof. Bysuch a size reduction the conversion process of the organic material isperformed even more quickly than without the size reduction.

Additionally, the pre-treating step may comprise the step of addingadditives to the fluid according to the present invention, whereby theconversion process is improved even further in regards to speed of theconversion time and in regards to the resulting product from theconversion of the organic material into hydrocarbon fuels. The productresulting from the conversion of the organic material may by addingthese additives be regulated, so that the resulting product may havevariable composition of oil, methanol, water, water soluble organics,water soluble salts, etc. It is then possible to adjust the recyclableproduct in regards to the wishes of the subsequent use of the products.

In one aspect of the present invention the step of pre-treating maycomprise the step of adjusting the pH of said fluid comprising saidorganic material to above 7. It hereby obtained to adjustment of the pHvalue in the fluid comprising the organic material at an early stage ofthe conversion process, whereby the process time for the conversion isreduced.

By the step of pre-treating the fluid comprising the organic material itis possible to increase the amount of solid-state material in the fluid,which again leads to a higher rate of conversion and thereby a higherproduction capacity. This results in a more efficient and cost savingconverting of organic material.

In another aspect of the present Invention the method may furthercomprise a step of separating particles from the fluid comprising theorganic material. By separating particles before contacting the fluidcomprising the organic material with the heterogeneous catalyst theproduct resulting from the conversion process, such as oil, is thensubstantially free of being bound to these particles and therefore muchmore reusable straight after this conversion process. A second process,such as an refinery is thereby dispensable.

In yet another aspect of the present invention the method may furthercomprise a second step of heating the fluid. The temperature of fluidcomprising the organic material is hereby adjustable just beforecontacting the heterogeneous catalyst, whereby the process is optimised,which leads to a reduced process time. Furthermore, by separating theparticles away from the fluid at such an early stage a substantiallyamount of energy for transporting the separated particles is saved,which again decreases the amount of energy spend in the conversionprocess as a total.

Additionally, the method may according to the invention comprise asecond separating of particles, which step is merely for safety reasonin regards to the first step of separating particles. This step reducesfor the same reasons as the first step of separating particles the totalamount of energy spend for the conversion process.

Furthermore, the method may according to the invention comprise a stepof cooling the fluid. By cooling the fluid the resulting product fromconverting of the organic material may be optimized in relations to thecomposition of product.

Advantageously, the step of cooling may according to the presentinvention be performed by heat exchanging with the first step of heatingand/or a step of pre-heating the fluid in the pre-treating step. It ishereby obtained to reuse the heat from the fluid, which needs to cooldown before the second part of conversion into the recyclable products,in the fluid in the first part of conversion process before contactingthe fluid with the heterogeneous catalyst. The total amount of energyfor the converting of organic material is thereby kept to a minimum.

Said method may according to one aspect the present invention furthercomprise a step of separation gas from the fluid, such as fuel gas. Byseparating this gas one kind of recyclable product is obtained, whichwas an objective of the invention.

The method may according to one aspect the present invention furthercomprise the step that the fuel gas is used for heating the fluid in thesecond heating step. By using the separated gas it is reused inconverting the organic material and therefore reusable.

Furthermore, the method may according to the invention further comprisea step of filtrating water and water soluble organics from oil and watersoluble salts in a first membrane-filter. By this separating arecyclable products is obtained and a further converting into recyclableproducts is possible.

In an aspect of the present invention the water and water solubleorganics are transformed into electricity in a direct methanol fuelcell. This is one way of using one of the recyclable products of thepresent invention. It may also be regarded as a subsequent step ofconverting the recycle products into a usable product in form ofelectricity.

The method may also according to another aspect of the present inventioncomprise a second step of filtering water soluble organics from thewater, such as an purification of methanol in a second membrane-filter.By this conversion step one recycle product is obtained.

Subsequently, said one or more membrane-filters may be selected from thegroup of membrane processes comprising ultra-filtration,nano-filtration, reverse osmosis or pervaporation or a combinationthereof. By this selection different kinds of recycle products areobtainable.

According to one aspect of the present invention, the water and watersoluble organics after the second filtering step may be transformed intodrinkable water in a process of reverse osmosis. By the methodcomprising the process of reverse osmosis one very usable recyclableproduct is obtained.

According to one aspect of the present invention, the water solubleorganic may comprising up-concentrated methanol may be re-circulated tothe pre-treating step. A further optimization of the converting methodis hereby obtained, and the converted product of up-concentratedmethanol is reused.

Additionally, the method may according to one aspect of the inventioncomprise a phase separator, whereby separation of oil as product isobtained.

According to one aspect of the present invention, the step of contactingthe organic material in the fluid with a heterogeneous catalyst may beperformed while the temperature is kept substantially constant. Bykeeping the temperature constant in the contacting step the contactingof the fluid with the heterogeneous catalyst is kept in the samecondition and the conversion is therefore constant throughout thecontacting step. A further advantage is that the equilibriums andreaction rates of the chemical reactions involved in the conversion arekept constant throughout the contacting step, thereby ensuringuniformity in the products formed by the conversion.

In another aspect of the present invention, the temperature in the stepof contacting may be in the range 200-650° C., such as in the range200-450° C., and preferably in the range 200-374° C., and even morepreferably in the range 250-374° C., such as in the range 275-350° C. Bykeeping these low temperatures the conversion process is using lessenergy in converting the same amount of organic material than at highertemperatures. A low temperature together with a pH value above 7decreases the corrosion of the materials used for the apparatus in whichthe present method is performed.

A low temperature in the contacting step increases the fraction of theorganic material being converted into hydrocarbon fuels, and thereby theoil production capacity of the contacting step. At such low temperaturesthe solubility of salts is high compared to higher temperature wherebythe conversion process is further advantageous due to almost no saltsdepositing occurs inside the apparatus. Furthermore, at such lowtemperatures the organic material is less converted into soot and tar,which products are not very recyclable. Finally such low temperatureallows construction of the apparatus from less corrosion resistantmaterials, further improving the competitive.

According to another aspect of the present invention, the pressure forsaid conversion may be in the range 225-600 bars, such as in the range225-400 bars and preferably in the range 225-350 bars, such as in therange 240-300 bars. By using pressures inside these ranges it isobtained that standard components and equipment may be used for thepresent method whereby the cost of the conversion process and apparatusis substantially decreased compared to the same at higher pressures.

Furthermore, the method may according to the invention further comprisethe step of contacting is done in less than 30 minutes, such as lessthan 20 minutes, preferably less 10 minutes, such as less than 7.5minutes, and even more preferably in the range 0.5-6 minutes, such as inthe range 1-5 minutes. By contacting the fluid at in a short period theconversion process time is decreased without decreasing the conversionprocessing of organic material substantially.

Additionally, the compound of at least one element of group IVB of theperiodic table may comprise zirconium and/or titanium according toanother aspect of the present invention. By using zirconium and/ortitanium as a heterogeneous catalyst the conversion process time isdecreased without decreasing the conversion processing of organicmaterial.

In another aspect of the present invention the compound of at least oneelement of group IVB of the periodic table may be on an oxide and/orhydroxide form or a combination of the two. By using the heterogeneouscatalyst on an oxide and/or hydroxide form the conversion process timeis decreased without decreasing the conversion processing of organicmaterial.

Advantageously, the compound of at least one element of group IVB of theperiodic table is at least partly on a sulphate or sulphide formaccording to another aspect of the present invention. By using theheterogeneous catalyst on a sulphate or sulphide form the conversionprocess time is decreased without decreasing the conversion processingof organic material.

According to one aspect of the present invention, the heterogeneouscatalyst may further comprise at least one element selected from thegroup consisting of Fe, Ni, Co, Cu, Cr, W, Mn, Mo, V, Sn, Zn, Si in anamount up to 20% by weight, such as an amount up to 10% by weight,preferably in an amount up to 5% by weight, such as up to 2.5% byweight. By using the aforementioned heterogeneous catalyst together withone or more elements of this group the conversion process time issubstantially decreased without decreasing the conversion processing oforganic material.

Furthermore, these elements may be on an oxide and/or hydroxide formaccording to another aspect of the present invention, whereby theconversion process time is further decreased without decreasing theconversion processing of organic material.

In yet another aspect of the present invention said heterogeneouscatalyst may be in the form of a suspended particles, tablets, pellets,rings, cylinders, a honey comb structure, a fibrous structure and/or acombination of these. The advantage of said heterogeneous catalyststructures is to control the flow distribution of the organic materialstream being contacted with the catalyst, while ensuring reasonablepressure drop and contact to all of the catalyst surface.

Additionally, said heterogeneous catalyst is at least partly containedin a reactor according to another aspect of the present invention. It ishereby possible to reuse that part of the catalyst, which is inside thereactor.

Advantageously, said reactor is a fixed bed reactor according to anotheraspect of the present invention. By using a fixed bed reactor, it ishereby possible to even more easily reuse that part of the catalyst,which is inside the reactor.

According to one aspect of the present invention, said heterogeneouscatalyst may have a BET surface area of at least 10 m2/g, such as 25m2/g, and preferably at least 50 m2/g, such as 100 m2/g, and even morepreferably at least 150 m2/g, such as at least 200 m2/g. By having thisBET surface area, the conversion process time is further decreasedwithout decreasing the quality of the conversion process, as sufficientcatalytic active surface area is ensured.

According to another aspect of the present invention, said heterogeneouscatalyst may comprise at least one surface area stabilizer selected fromthe group consisting of Si, La, Y or Ce or a combination thereof. Byhaving this surface stabilizer, the catalyst service lifetime time isfurther expanded without decreasing the quality of the conversionprocess.

Advantageously, said heterogeneous catalyst may according to one aspectof the present invention comprise said at least one surface areastabilizer in an effective amount up to 20% by weight, such as aneffective amount up to 10% by weight, preferably said surface areastabilizers in an effective amount up to 7.5% by weight, such as surfacestabilizers in an effective amount up to 5% by weight, and morepreferably said surface stabilizers are present in an effective amountfrom 0.5-5% by weight, such as 1-3% by weight. By having this surfacestabilizer in up to 20% by weight, the catalyst service lifetime isfurther expanded without decreasing the quality of the conversionprocess.

In yet another aspect of the present invention said heterogeneouscatalyst may have a BET surface area of at least 10 m2/g after 1000hours of use, such as BET surface area of at least 25 m2/g after 1000hours of use, and preferably a BET surface area of at least 50 m2/gafter 1000 hours of use, such as a BET surface area of at 100 m2/g after1000 hours of use, and even more preferably a BET surface area of atleast 150 m2/g after 1000 hours in use, such as at a BET surface area ofleast 200 m2/g after 1000 hours in use. By having this BET surface areaof at least 10 m2/g after 1000 hours of use, the conversion process timeis further decreased without decreasing the quality of the conversionprocess, as sufficient catalytic active surface area is ensured.

Furthermore, said heterogeneous catalyst is produced from red mudaccording to another aspect of the present invention. It is herebyobtained to use waste product in the converting of the organic material,which also is a waste product.

Additionally, the method may according to the invention further comprisethe step of re-circulating carbonates and/or hydrogen carbonates. Byre-circulating carbonates and/or hydrogen carbonates the method isreusing products resulting from the conversion method and an optimizingof the method is hereby obtained.

The concentration of said carbonates and/or hydrogen carbonates mayaccording to an aspect of the invention be at least 0.5% by weight, suchas at least 1% by weight, and preferably at least 2% by weight, such asat least 3% by weight, and more preferably at least 4% by weight, suchas at least 5% by weight. The carbonates and bicarbonates are importantactivators in the catalytic conversion performed by the homogenouscatalyst.

Furthermore, the method may according to the invention further comprisethe step of re-circulating at least one alcohol. By re-circulating atleast one alcohol the method is reusing products resulting from theconversion method and an optimizing of the method is hereby obtained.

According to one aspect of the present invention, said at least onealcohol may comprise methanol, whereby a very usable recyclable productis reused in optimizing the method.

According to another aspect of the present invention, the methanolcontent in said fluid may be at least 0.05% by weight, such as at least0.1% by weight, and preferably at least 0.2% by weight, such as at least0.3% by weight, and even more preferably at least 0.5% methanol byweight, such as at least 1% by weight. Methanol is involved in thechemical reactions responsible for producing the oil product, and in thechemical reactions destroying the radicals otherwise responsible forformation of soot and tar during the decomposition of the organicmaterial.

Advantageously, the method may according to another aspect of thepresent invention comprise the step of re-circulating a fluid containinghydrogen. By re-circulating a fluid containing hydrogen the method isreusing products resulting from the conversion method and an optimizingof the method is hereby obtained.

In yet another aspect of the present invention the hydrogen content ofsaid fluid corresponds to at least 0.001% by weight of the amount ofsaid organic material to be treated, such as at least 0.01% by weight ofthe amount of said organic material to be treated, and preferably 0.1%by weight of the amount of said organic material to be treated, such as0.2% by weight of the amount of said organic material to be treated, andeven more preferably the hydrogen content of the fluid is at least 0.5%by weight of the amount of said organic material to be treated, such asat least 10% by weight of the amount of said organic material to betreated. Hydrogen is involved in the chemical reactions producingsaturated oil compounds, and in the reactions destroying free radicals,otherwise leading to formation of soot and tar during the thermaldecomposition of the organic material during the conversion.

Furthermore, the method may according to the invention further comprisethe step of re-circulating at least one carboxylic acid. Byre-circulating at least one carboxylic acid the method is reusingproducts resulting from the conversion method and an optimizing of themethod is hereby obtained.

Additionally, said at least one carboxylic acid may comprise at leastone carboxylic acid having a chain length corresponding to 1-4 carbonatoms according to another aspect of the present invention. The said atleast one carboxylic acid corresponding to 1-4 carbon atoms is involvedin the chemical chain formation reactions producing the oil product.

Furthermore, said at least one carboxylic acid may comprise formic acidand/or acetic acid according to another aspect of the present invention.The said at least one carboxylic acid corresponding to 1-4 carbon atomsis involved in the chemical chain formation reactions producing the oilproduct.

Advantageously, the concentration of said carboxylic acid(s) in saidfluid may according to the present invention be at least 100 part permillion by weight, such as at least 250 part per million by weight, andpreferably at least 400 parts per million by weight, such as at least500 parts per million by weight. At this concentration level the oilproduct producing chemical reactions rates are sufficient to ensureconversion of the organic material to said oil product.

In one aspect of the present invention the method may comprise the stepof re-circulating at least one aldehyde and/or at least one ketone. Byre-circulating at least one aldehyde and/or at least one ketone themethod is reusing products resulting from the conversion method and anoptimizing of the method is hereby obtained.

In another aspect of the present invention said at least one aldehydeand/or at least one ketone comprises at least one aldehyde and/or atleast one ketone having a chain length corresponding to 1-4 carbonatoms. The said at least one aldehyde or ketone corresponding to 1-4carbon atoms is involved in the chemical chain formation reactionsproducing the oil product.

In yet another aspect of the present invention said at least onealdehyde and/or at least one ketone comprises formaldehyde and/oracetaldehyde. The said at least one aldehyde or ketone corresponding to1-4 carbon atoms is involved in the chemical chain formation reactionsproducing the oil product.

According to the present invention, the concentration of said at leastone aldehyde and/or at least one ketone in said fluid may be at least100 part per million by weight, such as at least 250 part per million byweight, and preferably at least 400 parts per million by weight, such asat least 500 parts per million by weight. At this concentration levelthe oil product producing chemical reactions rates are sufficient toensure conversion of the organic material to said oil product.

Advantageously, the homogeneous catalyst comprises potassium and/orsodium according to one aspect of the present invention. By usingpotassium and/or sodium as a homogeneous catalyst the conversion processtime is decreased without decreasing the conversion processing oforganic material, and the rates chemical reactions involved in the oilproduct formation are enhanced to facilitate production of said oilproduct.

Furthermore, according to another aspect of the present invention thehomogeneous catalyst may comprise one or more water soluble saltsselected from the group consisting of KOH, K₂CO₃, KHCO₃, NaOH, Na₂CO₃ orNaHCO₃ or a combination thereof. In combination with the carbon dioxideformed as part of the conversion of the organic material said salts areconverted into the carbonate involved in the chemical reactions asactivator.

In another aspect of the present invention the concentration of thehomogeneous catalyst may be at least 0.5% by weight, such as at least 1%by weight, and preferably at least 1.5% by weight, such as at least 2.0%by weight, and even more preferably above 2.5% by weight, such as atleast 4% by weight. At this concentration level the oil productproducing chemical reactions rates are sufficient to ensure conversionof the organic material to said oil product.

Additionally, said fluid comprises water according to another aspect ofthe present invention. Water is a cheap an very frequent fluid andtherefore by using water the cost to method of converting organicmaterial is kept to a minimum and the method may be used in all areas ofthe world.

According to one aspect of the present invention, said water may have aconcentration of at least 5% by weight, such as at least 10% by weight,and preferably at least 20% by weight, such as at least 30% by weight,and even more preferably at least 40% by weight. The organic material tobe converted must be pumpable.

The concentration of said water in said fluid may according to anotheraspect of the present invention be up to 99.5% by weight, such as up to98% by weight, and preferably up to 95% by weight, such as up to 90% byweight, and even more preferably up to 85% by weight, such as up to 80%by weight. By decreasing the water content the heat value of thefeedstock is increased, leading to increased oil production capacity atconstant processing cost, without sacrificing the pumpability of theorganic material to be converted.

In one aspect of the present invention said at least one carbonateand/or at least one hydrogen carbonate and/or at least one alcoholand/or at least one carboxylic acid and/or at least one aldehyde and/orat least one ketone may at least partly be produced by the conversion ofsaid organic material. By reusing a product resulting from theconversion process, the conversion process time is decreased withoutdecreasing the conversion processing of organic material. Furthermoreexpenses for treating an effluent stream are saved.

In another aspect of the present invention said at least one carbonateand/or at least one hydrogen carbonate and/or at least one alcoholand/or at least one carboxylic acid and/or at least one aldehyde and/orat least one ketone may be re-circulated after the step of contacting.It is hereby obtained that some of the resulting products from theconversion process is reused and that the conversion process time isdecreased without decreasing the conversion processing of organicmaterial.

Furthermore, at least part of a stream of said recirculation mayaccording to another aspect of the present invention be mixed in a ratiowith a feed stream of said fluid comprising said homogeneous catalystand organic material to be converted before entering the catalyticreactor. It is hereby obtained that some of the resulting products fromthe conversion process is reused and that the conversion process time isdecreased without decreasing the conversion processing of organicmaterial.

Additionally, the ratio of the re-circulating stream to the feed streamof said fluid may according to another aspect of the present inventionbe in the range 1-20, such as 1-10, and preferably within the range1.5-7.5, such as in the range 2-6, and more preferably in the range2.5-5. It is hereby obtained that some of the resulting products fromthe conversion process is reused and that the conversion process time isdecreased without decreasing the conversion processing of organicmaterial.

Advantageously, the conversion of said organic material may according toanother aspect of the present invention be at least 90%, such as atleast 95%, and preferably above 97.5% %, such as above 99%, and evenmore preferably above 99.5%, such as above 99.9%. The high conversionleads to maximization of the oil production capacity, and minimizes oreliminates the content of unconverted organic material in oil productand mineral product, thereby eliminating the need for a purificationstep.

According to one aspect of the present invention said reactor withheterogeneous catalyst may be subjected to a treatment with hotpressurised water at pre-selected intervals.

According to another aspect of the present invention, said treatmentwith hot pressurised water may have a duration of less than 12 hours,such as a duration of less than 6 hours, preferably a duration of lessthan 3 hours, such as a duration of less than 1 hour.

In another aspect of the present invention the interval between suchtreatment with hot pressurised water may be at least 6 hours, such as atleast 12 hours, preferably said interval between such treatment with hotpressurised water is at least 24 hours, such as at least one week.

By treating or flushing the reactor with hot pressurised water, the lifetime of the reactor is increased and the cost of the method is therebysubstantially decreased.

In yet another aspect of the present invention said organic material maybe selected from the group consisting of sludge, such as sewage sludge,liquid manure, corn silage, clarifier sludge, black liquor, residuesfrom fermentation, residues from juice production, residues from edibleoil production, residues from fruit and vegetable processing, residuesfrom food and drink production, leachate or seepage water or acombination thereof.

According to one aspect of the present invention, said organic materialmay comprise a lignocelulotic materials, selected from the groupconsisting of biomass, straw, grasses, stems, wood, bagasse, wine trash,sawdust, wood chips or energy crops or a combination thereof.

According to another aspect of the present invention, said organicmaterial may comprise a waste, such as house hold waste, municipal solidwaste, paper waste, auto shredder waste, plastics, polymers, rubbers,scrap tires, cable wastes, CCA treated wood, halogenated organiccompounds, PCB bearing transformer oils, electrolytic capacitors,halones, medical waste, risk material from meat processing, meat andbone meal, liquid streams, such as process or waste water streamscontaining dissolved and/or suspended organic material.

Advantageously, said sludge may according to another aspect of thepresent invention be sludge from a biological treatment process.

According to one aspect of the present invention said organic materialmay be sludge from a waste water treatment process.

In another aspect of the present invention said biological treatmentprocess may be part of a waste water treatment process.

Furthermore, said biological water treatment process may according toanother aspect of the present invention be an aerobic process.

Additionally, said biological water treatment process may be ananaerobic process according to another aspect of the present invention.

The method is capable of converting many kinds of organic material asmentioned above. Even though the method is performed at a relatively lowtemperature and a relatively low pressure the temperature and pressureis still sufficient to disinfect the resulting product. Which meansregardless what organic material the resulting products is usablewithout infecting risk, e.g. residues from residues from foodproduction, such as meat from a cow or a veal will not result in thespreading of the disease BSE. Likewise will virus, bacteria etc. fromthe organic material not be spread in a subsequent use of the resultingproducts.

Advantageously, said organic material may have been subjected to amechanical dewatering according to another aspect of the presentinvention. By dewatering the organic material the heat value of thefeedstock is increased, leading to increased oil production capacity atconstant processing cost, without sacrificing the pumpability of theorganic material to be converted.

Furthermore, said mechanically dewatered organic material may accordingto another aspect of the present invention have a dry solid content ofat least 10% by weight, preferably at least 15% by weight, morepreferably at least 20% by weight, most preferred 25% by weight.

By the pre-treatment step of the method it is obtained to increase thedry solid content, which again decreases the conversion process time.

Additionally, said organic material may according to another aspect ofthe present invention comprise a mixture of sludge, lignoceluloticmaterials or waste.

In another aspect of the present invention the concentration of saidorganic material in said fluid may be at least 5% by weight, such as atleast 10% by weight, preferably the concentration of said organicmaterial is at least 15% by weight, such as at least 200% by weight, andmore preferably the concentration of said organic material is at least30% by weight, such as at least 50% by weight.

Advantageously, the elements of group IA of the periodic table may beash obtained from combustion of biomass or ash from coal firingaccording to another aspect of the present invention.

By mixing the different organic materials it is obtained that lesscatalyst has to used in the further processing and/or that the rate ofthe processing time is increased.

The present invention further relates to the product obtained by theaforementioned method. Said product may according to the presentinvention comprise hydrocarbon in the form of oil. A resulting productwhich is very usable is hereby obtained in that oil is presently a verydemanded product all over the world. A product such as oil is possibleto obtain in that the method is performed at very low temperatures.

In another aspect of the present invention said fluid may have a feedcarbon content and a feed hydrocarbon content, where the hydrocarbon oilproduct comprises at least 20% of the feed carbon content, such as atleast 35% of the feed hydrocarbon content, preferably comprises saidhydrocarbon oil product at least 50% of the feed carbon content, such asat least 65% of the feed carbon content and more preferably saidhydrocarbon oil product comprises at least 80% of the feed carboncontent.

In another aspect of the present invention at least 20% of a energycontent in the feed stream may be recovered in said hydrocarbon oilproduct, such as at least 35% of the energy content, preferably is atleast 50% of the energy content in the feed recovered in saidhydrocarbon oil product, such as at least 65% of the feed energy contentand even more preferable at least 80% of said feed energy content isrecovered in said hydrocarbon oil product.

Furthermore, said hydrocarbon oil product comprises hydrocarbons with 12to 16 carbon atoms according to another aspect of the present invention.

Advantageously, said hydrocarbon oil product may be substantially freeof sulphur according to another aspect of the present invention.

Additionally, said hydrocarbon oil product may be substantially free ofhalogens according to another aspect of the present invention.

By the method according to the present invention a hydrocarbon oilproduct free of sulphur and/or halogens is hereby obtained. Such oilsfree of sulphur and/or halogens is very recyclable into new forms ofenergy without polluting the surroundings with reactions caused bysulphur and/or halogens.

Said hydrocarbon oil product may according to one aspect of the presentinvention comprise fatty acid esters and/or fatty acid methyl esters.The oxygen content of the fatty acid esters and methyl esters is knownto improve the properties of the hydrocarbon oil as transportation fuel,due to the reduced particle emission from the combustion of the fuel.

The hydrocarbon oil product may have diesel-like properties according toanother aspect of the present invention. The diesel-like hydrocarbonfuel might be mixed directly into conventional diesel oil, therebysaving the cost of refining the oil product.

Furthermore, the hydrocarbon oil product may have a oxygen content inthe range 0.1-30% according to another aspect of the present invention.The oxygen content of the hydrocarbon fuel is known to improve theproperties as transportation fuel, due to the reduced particle emissionfrom the combustion of the fuel.

Additionally, the hydrocarbon oil product may be adsorbed on the surfaceof a mineral product according to another aspect of the presentinvention. This oil containing mineral product is an improved startingmaterial for molten mineral processing processes.

The hydrocarbon product may also comprise methanol according to anotheraspect of the present invention. By further purification a purifiedmethanol product might be obtained, which is preferred fuel for fuelcells or additive to gasoline for production of sustainabletransportation fuels.

In another aspect of the present invention said hydrocarbon productcomprising methanol may comprise at least 20% of the feed carboncontent, such as at least 35% of the feed carbon content, preferablycomprises said methanol product at least 50% of the feed carbon content,such as at least 65% of the feed carbon content and more preferablycomprises said methanol product at least 80% of the feed carbon content.By further purification a purified methanol product might be obtained,which is preferred fuel for fuel cells or additive to gasoline forproduction of sustainable transportation fuels.

In yet another aspect of the present invention at least 20% of theenergy content in the feed may be recovered in said hydrocarbon productcomprising methanol, such as at least 35% of the energy content in thefeed is recovered in said hydrocarbon product comprising methanol,preferably is at least 50% of the energy content in the feed recoveredin said hydrocarbon product comprising methanol, such as at least 65% ofthe feed energy content is recovered in said hydrocarbon productcomprising methanol and more preferably is at least 80% of said feedenergy content recovered in said hydrocarbon product comprisingmethanol. By further purification a purified methanol product might beobtained, which is preferred fuel for fuel cells or additive to gasolinefor production of sustainable transportation fuels.

The present invention further relates to the use of the aforementionedproduct for driving an engine or generator, for power production in anoil fired power plant, for process heating or domestic heating. Theseare all means of producing energy from a sustainable source, yet withouthaving to replace or renew the hardware installations or infrastructureestablished for energy production from fossil fuels.

Furthermore, the present invention relates to the use of theaforementioned product as a blending component in petrodiesel orgasoline or in a suspension fired system or in a process for moltenmineral processing. These are all means of producing energy from asustainable source, yet without having to replace or renew the hardwareinstallations or infrastructure established for energy production fromfossil fuels.

Additionally, the present invention relates to the use of theaforementioned for producing a fertilizer product or for producing cleanwater stream. Said clean water stream may furthermore have drinkingwater quality.

The present invention additionally relates to an apparatus forconverting an organic material into hydrocarbons, comprising:

-   -   a pre-conversion system and a product recovery system, said        pre-conversion system comprises    -   a first heating unit for heating a feed of fluid comprising        organic material    -   a catalyst reactor for contacting the feed of fluid comprising        organic material, and    -   an adjusting unit for adjusting the fluid to have a pH value of        above 7, and said product recovery system comprises    -   membrane-filter for separating a first stream of oils and water        soluble salts in from a second stream of water and water soluble        organics.

According to one aspect of the present invention, the pre-conversionsystem may further comprise a storage for feeding organic material tothe fluid in a feeding direction.

Furthermore, the pre-conversion system may further comprise apre-treating unit situated after the feedstock and before the firstheating unit in the feeding direction, according to another aspect ofthe present invention. By pre-treating the fluid comprising the organicmaterial it is possible to increase the amount of solid-state materialin the fluid, which again leads to a higher rate of conversion andthereby a higher production capacity. This results in a more efficientand cost saving converting of organic material.

Additionally, the pre-conversion system may according to the presentinvention further comprise a first particle separating unit situatedafter the first heating unit in the feeding direction. By separatingparticles before contacting the fluid comprising the organic materialwith the heterogeneous catalyst the product resulting from theconversion process, such as oil, is then substantially free of beingbound to these particles and therefore much more reusable straight afterthis conversion process. A second process, such as an refinery isthereby dispensable.

Said pre-conversion system may according to the invention furthercomprise a second heating unit situated after the first particleseparating unit and before the catalyst reactor in the feedingdirection. It is hereby possible to optimize the temperature beforeentering the fluid into the reactor and thereby an optimization of theconversion process.

In another aspect of the present invention the pre-conversion system mayfurther comprise a second particle separation unit after the catalystreactor in the feeding direction. This particle separating unit is forthe same reason as above advantageous.

In yet another aspect of the present invention the pre-conversion systemmay further comprise means for re-circulating part of the feed of fluidafter the catalyst reactor into the feed of fluid before the secondheating unit in the feeding direction. It is hereby obtained that someof the resulting products from the conversion process is reused and thatthe conversion process time is decreased without decreasing theconversion processing of organic material.

Furthermore, the first heating unit may according to the presentinvention comprise a first heat exchanger, which besides heating coolsthe fluid from pre-conversion system before entering the productrecovery system. It is hereby obtained to reuse energy inside theapparatus and thereby same energy in the total amount of energy used inconverting the organic material.

Additionally, the pre-treating unit may according to the inventionfurther comprise a heat exchange, which besides heating the fluid in thepre-treating system cools the fluid from pre-conversion system beforeentering the product recovery system. This heat exchanger is for thesame reason as above advantageous

The pre-treating unit may further comprise a first expansion unit, whichis situated between the first heat exchanger and the second heatexchanger, according to an aspect of the present invention. It is herebyobtained to produce gas, such as fuel gas.

In one aspect of the present invention the product recovery system mayfurther comprise a gas separating unit for separation of gas, such asfuel gas, the gas separating unit is situated after the second heatexchanger and before the first membrane-filter in the feeding direction.It is hereby obtained to separate the aforementioned gas, such as fuelgas from the rest of the fluid.

In another aspect of the present invention the product recovery systemmay further comprise means for re-circulating said gas, such as fuel gasfor heating the fluid in the second heating unit. It is hereby obtainedthat some of the resulting products from the conversion process isreused and that the conversion process time is decreased withoutdecreasing the conversion processing of organic material.

In yet another aspect of the present invention the product recoverysystem may further comprise a second expansion unit situated after thefirst membrane-filter in the feeding direction. It is hereby obtained toproduce oil out from the fluid, and thereby a very

Furthermore, the product recovery system may according to one aspect ofthe present invention further comprise a phase separator unit forseparation of oil from the first stream, said phase separator unit issituated after the membrane-filter in the feeding direction. It ishereby obtained to separate oil from the fluid.

Additionally, the product recovery system may according to anotheraspect of the present invention further comprises means forre-circulating part of the first stream into the pre-treating unit ofthe pre-conversion system. It is hereby obtained that some of theresulting products from the conversion process is reused and that theconversion process time is decreased without decreasing the conversionprocessing of organic material.

Advantageously, the product recovery system may according to anotheraspect of the present invention further comprise direct methanol fuelcell for generating electricity from the second stream.

According to yet another aspect of the present invention the productrecovery system further comprises one or more membrane-filters may beselected from the group of membrane processes comprisingultra-filtration, nano-filtration, reverse osmosis or pervaporation or acombination thereof.

Furthermore, the product recovery system may according to an aspect ofthe invention further comprise the second membrane-filter for separatinga purified methanol compound from the second stream.

In another aspect of the present invention the product recovery systemmay further comprise means for re-circulating the purified methanolcompound from the second stream to the pre-treating unit of thepre-conversion system. It is hereby obtained that some of the resultingproducts from the conversion process is reused and that the conversionprocess time is decreased without decreasing the conversion processingof organic material.

The present invention further relates to a plant comprising theaforementioned apparatus, for producing the aforementioned product byusing the aforementioned method.

In one aspect of the present invention the plant may comprise means forsupplying organic material to the apparatus and means for removal of theproducts from the apparatus.

In another aspect of the present invention the plant may furthercomprise a refinery

The present invention further relates to a heterogeneous catalyst foruse in a method for converting an organic material into hydrocarbons,comprising a compound of at least one element of group IVB of theperiodic table and/or alpha-alumina.

Additionally, the compound of at least one element of group IVB of theperiodic table may comprise zirconium and/or titanium according to anaspect of the present invention.

Furthermore, the compound of at least one element of group IVB of theperiodic table may be on an oxide and/or hydroxide form or a combinationof the two according to an aspect of the present invention.

Advantageously, the compound of at least one element of group IVB of theperiodic table may be at least partly on a sulphate or sulphide formaccording to an aspect of the present invention.

In another aspect of the present invention the heterogeneous catalystmay further comprise at least one of element selected from group of Fe,Ni, Co, Cu, Cr, W, Mn, Mo, V, Sn, Zn, Si in an amount up to 20% byweight, such as an amount up to 10% by weight, preferably in an amountup to 5% by weight, such as up to 2.5% by weight.

Furthermore, these elements are on an oxide and/or hydroxide formaccording to another aspect of the present invention.

Additionally, the heterogeneous catalyst is in the form of suspendedparticles, tablets, pellets, rings, cylinders, a honeycomb structureand/or a combination of these according to yet another aspect of thepresent invention.

In yet another aspect of the present invention the heterogeneouscatalyst may have a BET surface area of at least 10 m2/g, such as 25m2/g, and preferably at least 50 m2/g, such as 100 m2/g, and even morepreferably at least 150 m2/g, such as at least 200 m2/g.

Advantageously, the heterogeneous catalyst further comprises at leastone surface area stabilizer selected from the group of Si, La, Y and/orCe according to an aspect of the present invention.

Subsequently, the heterogeneous catalyst may according to an aspect ofthe present invention comprise said at least one surface area stabilizerin an effective amount up to 20% by weight, such as an effective amountup to 10% by weight, preferably said surface area stabilizers in aneffective amount up to 7.5% by weight, such as surface stabilizers in aneffective amount up to 5% by weight, and more preferably said surfacestabilizers are present in an effective amount from 0.5-5% by weight,such as 1-3% by weight.

In another aspect of the present invention the heterogeneous catalystmay have a BET surface area of at least 10 m2/g after 1000 hours of use,such as BET surface area of at least 25 m2/g after 1000 hours of use,and preferably a BET surface area of at least 50 m2/g after 1000 hoursof use, such as a BET surface area of at 100 m2/g after 1000 hours ofuse, and even more preferably a BET surface area of at least 150 m2/gafter 1000 hours in use, such as at a BET surface area of least 200 m2/gafter 1000 hours in use.

Finally, the heterogeneous catalyst may be produced from red mudaccording to an aspect of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will in the following be described with referenceto the accompanying drawings, in which:

FIG. 1 show schematic drawing of laboratory scale set-up,

FIG. 2 shows a general process flow sheet,

FIG. 3 shows one aspect of product recovery according to the presentinvention,

FIG. 4 shows another aspect of product recovery according to the presentinvention,

FIG. 5 shows yet another aspect of product recovery according to thepresent invention, and

FIG. 6 shows yet another aspect of product recovery according to thepresent invention.

The drawings are schematically and shown for the purpose ofillustration.

FIG. 1 is a schematic drawing of the laboratory set-up used for thetests given in the examples. The pre-treated fluid containing thehomogeneous catalysts and organic material to be converted is suppliedto the system at the position A. The fluid is pressurized by means ofthe pump 1 and is heated to approximately 230 C in the heater 2comprising a heat exchanger and a temperature controller TIC. A secondfluid is supplied to the system at position B. This stream ispressurized by means of the pump 3 and heated in the heater 4 to thetemperature necessary to obtain the desired conversion temperature ofthe mixed fluid streams at position 4, comprising a heat exchanger and atemperature controller TIC. The heterogeneous catalyst is located in thetubular catalytic reactor 5. After contact with the heterogeneouscatalyst, the fluid containing the converted organic material is cooledto ambient temperature in the cooler 6, and filtered in the filter 7 forseparation and collection of suspended particles. Subsequently the fluidis expanded to ambient pressure over the valve 8. The system pressure ismaintained by controlling the flow through 8, utilizing the pressurecontroller PIC. The expanded fluid temperature is measured with thethermocouple 9. The liquid fraction of the stream is collected in aliquid trap 10, and the gas is vented off from the trap at position G.The flow rate of the produced gas is continuously measured by a gasmeter placed in H (not shown). The composition of the gas is analysed bygas chromatography (not shown) of a small sample taken through I, atcontrolled pressure established by the flow control valve and thepressure controller (PIC) 11.

FIG. 2 shows a schematic drawing of a preferred aspect of a methodaccording to the present invention. Organic material for conversion isreceived in a feed storage (not shown on the figure). Said organicmaterial may comprise a wide range of biomass and wastes, and may alsocomprise fossil fuels such coal, shale, orimulsion, heavy fractions ofcrude oil etc. Many aspects according to the present invention involvetreatment of organic material from a mixture of different sources ofmaterial as just mentioned.

The feed storage will typically have a capacity corresponding to threedays of plant operation. The feed storage is preferably a concealed andagitated silo, such as an agitated concrete silo. A fluid containing theorganic material is pumped to the pre-treatment step 1 at position A.

The first part of the pre-treatment comprises in this aspect a sizereduction of the feed e.g. by cutting, grinding, milling and/or sievingthe material. This size reduction may be an integral part of feedingpump (not shown). During the feeding operation to the pre-treatment thepressure of the fluid containing the organic material to be treated isincreased to a pressure in the range 4-15 bars. In the second part ofthe pre-treatment the fluid containing said organic material istypically maintained in a pre-treatment vessel for a period of 0.5-2hours. The pre-treatment vessel is preferably an agitated vessel, whichis maintained at a temperature of 100-170 C, and preferably in the range110 to 140 C. The energy for this pre-heating of said fluid comprisingsaid organic material to be converted is preferably supplied, byrecovering heat from one of the process streams to be cooled. In thefigure this is illustrated by integrating the heat exchanger 2 in vesselfor recovery of heat from the process stream D.

The pH in the pre-treatment vessel is adjusted to a value above 7, andpreferable in the range 8-10. This pH adjustment is in many aspectsaccording to the present invention performed by adding additives to thevessel either directly into the pre-treatment vessel and/or through itsinlet, e.g. by adding a base, which may also comprise an element ofgroup IA of the periodic table. Non-limiting examples of such additivesare KOH, NaOH, K₂CO₃, Na₂CO₃, ash from biomass or coal combustion. Suchadditives may be added to the vessel through a stream S either streaminginto stream A or streaming directly into the vessel 1. Feed of thestream S may be provided by a feeding pump (not shown).

During the residence in the pre-treatment vessel larger molecules suchas cellulose, hemicellulose and lignin are hydrolyzed, and cells frombiomass addition is opened facilitating the release of cell contents,such as salts. For a number of potential feedstock this cell openinginvolve release of catalysts such as potassium from the feedstockitself, thereby allowing for a very efficient process. A number of otheradditives may also enhance the pre-conversion of the organic materialand are further advantageous for the subsequent processing. Such otheradditives include alcohols, such as methanol, carboxylic acids,aldehydes, and/or ketones. In a preferred aspect of the invention anumber of such additives being utilized in the pre-treatment, areproduced in-situ in the process and re-circulated to the pre-treatmentstep as shown by the streams E and F. Typical compositions of theserecirculation streams is further described in relation to the FIGS. 3-5.

A fluid stream containing pre-converted organic material is withdrawnfrom pre-treatment vessel by the feed pump 3, and pressurized to theoperating pressure e.g. 250 bars. The feed pump may comprise a plungerpump.

After pressurization the fluid containing the pre-converted organicmaterial, the homogeneous catalyst and other additives is heated in thefirst heating step 4 by heat exchange with the hot converted productstream from the catalytic reactor. The temperature of the fluidcontaining the pre-converted organic material will in many applicationsaccording to the present invention be in the order of 20-30° C. belowthe operating temperature of the catalytic reactor. During this firstheating step the organic material in the feed is further thermallydecomposed. A number of undesirable side reactions may proceed duringthis thermal decomposition, such soot and char formation. Besidesreducing the overall efficiency of the process, this may lead tooperational problems such as plugging or reduced efficiency of heatexchanger, and deposition on downstream equipment. The aforementionedadditives reduce these undesirable side reactions and enhance furtherthe conversion of the organic material into desirable products.

From the heat exchanger 4, the fluid containing said pre-convertedorganic material may pass a first particle separation device 5 forcollection of suspended particles, which may be formed during saidpre-conversion during heat-up. This particles separation device 5 maycomprise any conventional means for particle separation, e.g. a cyclone,a filter, a gravimetric settling chamber etc. Particles collected arewithdrawn from the process shown by the stream B.

After the first particle separation device 5 the fluid containing saidpre-converted organic material is mixed with a re-circulating streamfrom the catalytic reactor. This mixing will typically increase thetemperature of the mixed fluid with 10-20 C, and the recirculation willfurther introduce desirable compounds for the further conversion intothe feed. After mixing with the re-circulation stream the mixed fluidpasses to a trimheater (second heating unit) 6, wherein the temperatureis raised to the operating temperature of the catalytic reactor 7. Thetrimheater 6 may in many aspects according to the present invention be agas or oil fired heater, and is preferably at least partly fuelled byre-circulating gas and/or other fuel products produced in the process.In a preferred aspect, this trimheater is fuelled by re-circulating theproduced gas denoted I in FIG. 3. The re-circulation of said producedgas I may include a purification step.

In the catalytic reactor 7, the fluid containing homogeneous catalyst,additives, and pre-converted organic material is contacted with theheterogeneous catalyst. The heterogeneous catalyst will typically becontained in a tubular fixed bed, and the catalytic reactor may comprisemultiple tubular fixed beds. During the conversion a dissolved fuel gas,a water soluble organics and an oil is generally produced. The productdistribution is adjustable within a wide range of concentration ofresulting products as shown in the examples below, and may be controlledby selecting a suitable combination of residence time, re-circulationflow rate, reaction temperature, and concentration of homogeneouscatalyst and additives.

Part of the product stream from the catalytic reactor is re-circulatedby the pump 8, and mixed with the fluid containing the pre-convertedorganic material as described above.

The remaining part corresponding to the mass flow of the fluidcontaining the pre-converted organic material before mixing with there-circulating stream is withdrawn to the second particle separationdevice 9. As for the first particle separation device this secondparticles separation device may comprise any conventional means forparticle separation e.g. a cyclone, a filter, a gravimetric settlingchamber etc. The main feature is to provide a hot separation ofpotential suspended particles produced oil prior to cooling andexpansion to avoid adsorption of the oil to the suspended particles.However, in a number of applications of the present invention e.g. forfeedstock with a low ash content this particle separation device may beoptional. Particles collected in the second particle separation deviceare withdrawn from the process shown by the stream C.

Subsequent to the passage of the second particle separation device thefluid stream is cooled in by heat exchange with the feed stream in theheat exchanger 4, and in the heat exchanger 2 and expanded to a pressurein the range 75-225 bars over the expansion valve 10, and separated inthe product recovery system 11. Some of the separated fluid stream fromthe product recovery system 11, such as the streams F and/or E may bere-circulated to the pre-treatment step as described above. The productrecovery system 11 is further illustrated and described below in theFIGS. 3-6.

The separation system, illustrated in FIG. 3, comprises a gas-liquidseparator 12, separating the gas products in stream I and the liquidproducts in stream J. In an aspect the gas product is used internallyfor fuelling the trimheater 6. The liquid products are further separatedin a first membrane filter 13. The membrane filtration separation ispressure driven, and in many applications applying a nano- orultrafiltration membrane. The filtration retentate in stream L includesparts of the feed water, the oil product and the dissolved inorganiccompounds, e.g. salts from the feedstock and the homogenous catalyst.The oil product is separated from stream L in an oil separator (phaseseparator unit) 14 operating at atmospheric conditions, and forming theoil product stream H. The remaining water and dissolved inorganiccompounds forms stream O. The main part of stream O is recycled to thepre-conversion 1, 2 in stream E, thereby recycling the homogenouscatalyst, while a purge stream P is discharged to balance the inorganiccompound input from the feedstock.

The further processing of the membrane filtration permeate, denotedstream K, is illustrated in FIG. 4-6. Stream K contains smaller watersoluble organics like C 1-4 alcohols and carboxylic acids.

In one aspect illustrated in FIG. 4 stream K is fed to a separation unit(membrane filter) 15, producing pure water of drinking water quality instream G and a stream of water soluble organics in stream F. Theseparation unit 15 is in an aspect of the invention a reverse osmosismembrane unit, comprising a multitude of membrane modules. The retainedwater soluble organics in stream F are recycled to the pre-conversionstep 1, 2.

In a further aspect, illustrated in FIG. 5, stream K is split into aconcentrated water soluble organics stream F and an organics depletedwater stream Q. The separation unit 16 involved is in many applicationsa membrane separation driven by temperature or concentration gradients,like membrane distillation or pervaporation.

The water stream Q is further purified in a polishing step 17, producingthe pure water stream G. The polishing step 17 is preferably anactivated carbon filter or like means for absorption of very lowconcentrations of impurities from a water stream.

In an aspect illustrated in FIG. 6 the water soluble organic stream K isfed to a direct methanol fuel cell 18, producing electricity and aprocess water stream R. The direct methanol fuel cell 18 might includefeed stream and effluent conditioning steps.

EXAMPLES Illustrative Example 1 Conversion of Sewage Sludge

Anaerobic digested sewage sludge below was converted according to themethod of the present invention in the laboratory scale plant shown inFIG. 1.

The dry matter content of the sewage sludge was 5%. The main componentsof the dry matter in weight % were:

-   -   C=28.30%    -   H=4.33%    -   N=3.55%    -   O=28.40%    -   P=4.49%    -   Al=7.77%    -   Si=7.44%    -   Ca=6.95%    -   Fe=3.17%    -   K=1.62%

An elemental analysis of sewage sludge dry matter was further analyzedby induced coupled plasma (ICP) revealing the following composition:

C [%] O [%] Al [%] H [%] Ca [%] Si [%] N [%] P [%] K [%] 30.9 30.5 6.155.2 5.03 4.98 4.66 4.62 2.36 Mn Cl [%] S [%] Fe [%] Na [%] Mg [%] Zn [%]Ti [%] Ba [%] [%] 1.13 1.09 1.04 0.938 0.875 0.226 0.195 0.0652 0.0375

The combustible fraction amounts to 58% of the dry matter content, witha heat value of 22.2 MJ/kg, which translates into a calorific value of476 KJ/kg in the sewage sludge as received.

Prior to the test the sewage sludge was pre-treated by sizing to lessthan 1 mm by cutting longer particles by a Seepex macerator (type25/15-I-I-F12-2) and milling by a colloid mill (Probst und Class, typeN100/E), and filtered by a screen basket filter (mesh width 1 mm).

Subsequently 1.5% by weight of potassium in the form of potassiumcarbonate was added to the resulting slurry. The pH value of the slurrywas 9.0.

125 ml of ZrO₂ heterogeneous catalyst stabilized with 2.2 atomic mole %of Si. The catalyst in the form of cylindrical pellets of 3 mm lengthand a diameter of 3 mm was added to the tubular reactor.

63 g/h of the pre-treated sewage sludge was pressurized to 250 bars andheated to 230 C in the pre-heating step. This stream was mixed with 393g/h of pressurized water heated to a temperature so as to obtain asubstantially constant temperature of 360±5 C after mixing.

The mixed flow was subsequently contacted with the heterogeneouscatalyst in the reactor. The feed to water ratio translates into a waterto feed ratio of 6:1, and the total flow of 456 g/h translates into acontact time of approximately 4 minutes.

After to the contact with the heterogeneous catalyst, the fluidcontaining the converted organic material is cooled to ambienttemperature, filtered through a particle filter for collection ofsuspended particles, and expanded to ambient pressure. The liquidfraction on the stream was collected in a liquid trap, and the gas isvented off.

The experiment resulted in three product streams, a gas, an aqueousproduct and a solid precipitate. Samples for analysis was collected fora period of 15.5 hours.

Gas Analysis

The flow rate and composition of the produced gas was measuredcontinuously by a gas meter with sampling. The composition was measuredby gas chromatography.

The analysis of the gas phase revealed the following results:

Gas analysis Hydrogen [vol. %] 55.13 Carbon dioxide [vol. %] 31.92Carbon monoxide [vol. %] 0.00 Methane [vol. %] 12.87 Ethene [vol. %]0.00 Ethane [vol. %] 0.00 Propene [vol. %] 0.00 Propane [vol. %] 0.00C4-compounds [vol. %] 0.00 Total [vol. %]: 99.92 Total amount of carbon,g 0.91Liquid Analysis

The liquid product was contained suspended particles. The filteredliquid was analyzed by ion chromatography, Induced Plasma Emission (ICP)and high temperature total carbon analyzers and mass spectrometry.

The analysis of the liquid phase revealed the following results:

Liquid analysis pH 8.32 Total Organic Carbon (TOC), [ppm by weight]726.8 Total Inorganic Carbon (TIC), [ppm by weight] 361.5 Total Carbon,[ppm by weight] 1088.3 Methanol [ppm by weight] 600 Ethanol [ppm byweight] 300 Acetic acid [ppm by weight] 332.7 Formic acid [ppm byweight] 10.3 Acetaldehyde [ppm by weight] 104.9 Total amount of carbonin liquid 9.30 g

The inorganic carbon content in the liquid was found primarily to be dueto the presence of carbonate.

Solid Analysis

The solid fractions was analyzed by means of a total carbon analyzer andby elemental analysis by an induced coupled plasma analyzer (ICP). Anorganic phase was found to be adsorbed to the inorganic particles underthe experimental conditions used.

This organic phase was extracted prior to the solid analysis usingCH₂Cl_(2,). The extractable fraction of the organic carbon was found tobe an oil phase, primarily consisting of saturated hydrocarbons with achain length of 12 to 16 carbon atoms, and there for comparable to fuelor diesel oil. The oil contained 2-hexadecanone, heptadecane,6,10-dimethyl-2-undecanone, hexadecane, 3-methyl-indole, 2-tridecanoneand other compounds. A sulphur and halogen analysis performed at theextracted oil, showed that the oil was essentially free of sulphur andhalogen compounds. The total amount of oil extracted from the solids was3.86 g and the total amount of carbon found in the oil phase wasequivalent to 3.28 g.

No carbon was detected in the solid product after extraction of adsorbedoil, indicating 100% conversion of the organic material in the feed. Thesame result can be concluded from the carbon balance below:

Carbon Balance

Input C: Output C: Sewage sludge: 13.81 g 0.91 g gas C

4.97% K₂CO₃: 4.51 g 4.34 g TIC liquid

23.68%  9.3 g TOC liquid

50.74%  0.0 TOC solid

0.00% 3.28 g C in oil

17.9% Σ 18.33 g Σ 17.83 g conversion

97.3%Energy Balance:

Heat Value Amount Energy Fraction Component [kJ/kg] [g] [% of energyinput with feed] Feed sludge 476 976.5 Methane 50,400 0.25 2.71 Hydrogen240,103 0.21 10.8 Methanol 19,918 13.67 58.6 Oil 41,900 3.86 34.8 Sum107.0

Illustrative Example 2 Conversion of Sewage Sludge

Anaerobic digested sewage sludge with characteristics as given above inexample was preheated and converted using the same catalyst andexperimental set-up.

140 g/h of the pretreated sewage sludge was pressurized to 250 bar andheated to 230 C in the pre-heating step. This stream was mixed with 414g/h of pressurized water heated to a temperature so as to obtain asubstantially constant temperature of 300±5 C after mixing.

The mixed flow was subsequently contacted with the heterogeneouscatalyst in the reactor. The feed to water ratio translates into a waterto feed ratio of 3:1, and the total flow of 545 g/h translates into acontact time of 3.3 minutes.

After to the contact with the heterogeneous catalyst, the fluidcontaining the converted organic material is cooled to ambienttemperature, filtered through a particle filter for collection ofsuspended particles, and expanded to ambient pressure. The liquidfraction on the stream is collected in a liquid trap, and the gas isvented off.

The experiment resulted in three product streams, a gas, an aqueousproduct and a solid precipitate. Samples for analysis was collected fora period of 10.5 hours.

Gas Analysis

The analysis of the gas phase revealed the following results:

Gas analysis Hydrogen [vol. %] 31.36 Carbon dioxide [vol. %] 41.17Carbon monoxide [vol. %] 2.25 Methane [vol. %] 24.22 Ethene [vol. %]0.00 Ethane [vol. %] 0.00 Propene [vol. %] 0.00 Propane [vol. %] 0.00C4-compounds [vol. %] 0.00 Total [vol. %]: 99.00 Total amount of carbon,g 0.54Liquid Analysis

The analysis of the liquid phase revealed the following results:

Liquid analysis pH 7.42 Total Organic Carbon (TOC), [ppm by weight]985.1 Total Inorganic Carbon (TIC), [ppm by weight] 439.3 Total Carbon,[ppm by weight] 1424.4 Methanol [ppm by weight] 800 Ethanol [ppm byweight] 0 Acetic acid [ppm by weight] 347.2 Formic acid [ppm by weight]43.2 Acetaldehyde [ppm by weight] 156.5 Total amount of carbon in liquid13.33 g

The inorganic carbon content in the liquid was found primarily to be dueto the presence of carbonate.

Solid Analysis

The solid fractions was analyzed by means of a total carbon analyzer. Anorganic phase was found to be adsorbed to the inorganic particles underthe experimental conditions used.

This organic phase was extracted prior to the solid analysis usingCH₂Cl_(2,). The extractable fraction of the organic carbon was found tobe an oil phase, primarily consisting of saturated hydrocarbons with achain length of 12 to 16 carbon atoms, and there for comparable to fuelor diesel oil. The oil contained 2-hexadecanone, heptadecane,6,10-dimethyl-2-undecanone, hexadecane, 3-methyl-indole, 2-tridecanoneand other compounds. The total amount of oil extracted from the solidswas 12.73 g and the total amount of carbon found in the oil phase wasequivalent to 10.83 g.

No carbon was detected in the solid product after extraction of adsorbedoil, indicating 100% conversion of the organic material in the feed.

Carbon Balance

Input C: Output C: Sewage sludge: 20.58 g 0.54 g gas C

1.97% K₂CO₃: 6.78 g 6.43 g TIC liquid

23.5% 6.3 g TOC liquid

23.02%  0.0 TOC solid

0.00% 10.83 g C in oil

39.58%  Σ 27.36 g Σ 24.1 g conversion

88.1%Energy Balance

Heat Value Amount Energy Fraction Component [kJ/kg] [g] [% of energyinput with feed] Feed sludge 476 1470 Methane 50,400 0.28 2.01 Hydrogen240,103 0.07 2.40 Methanol 19,918 9.30 26.37 equivalents Oil 41,90012.73 76.2 Sum 107.0

Illustrative Example 3 Conversion of Corn Silage

Corn silage was pretreated and converted using the same catalyst andexperimental set-up as described above in example 1 and 2.

Prior to the test the sewage sludge was pretreated by sizing to lessthan 1 mm by cutting longer particles by a Seepex macerator (type25/15-I-I-F12-2) and milling by a colloid mill (Probst und Class, typeN100/E), and filtered by a screen basket filter (mesh width 1 mm).

Subsequently 1.5% by weight of potassium in the form of potassiumcarbonate was added to the resulting slurry. The pH value of the slurrywas 9.6.

The characteristics of the corn silage after the pretreatment was thefollowing:

Corn silage feedstock Dry matter content [% weight] 11.29 Inorganicfraction of dry matter [% 29.4 Weight] Density [kg/m³] 1.0099 pH 9.6Heat of combustion¹ [kJ/kg] 1435 ¹Based on 18 MJ/kg heat of combustionfor the organic fraction of the dry matter.

The inorganic content of the dry matter was mainly the added potassiumcarbonate, accounting for approximately ¾ of the dry matter inorganiccompounds.

GC-MS analysis of the corn silage feedstock revealed numerous compounds,but all were present in concentrations too low for identification.Particularly aromatics like phenols were not found in any significantamount.

The dry matter content of the corn silage feedstock was analyzed,revealing the following composition:

Corn silage dry matter TC [mg/kg] 325000 Mo [mg/kg] 7.82 TOC [mg/kg]315000 N [mg/kg] 6960 Al [mg/kg] 233 Na [mg/kg] 825 Ca [mg/kg] 2023 Ni[mg/kg] 11.1 Cl [mg/kg] 1682 S [mg/kg] <0.1 Cr [mg/kg] 28 Si [mg/kg]2090 Fe [mg/kg] 4571 Zr [mg/kg] 2.24 K [mg/kg] 112350

140 g/h of the pretreated sewage sludge was pressurized to 250 bar andheated to 230 C in the pre-heating step. This stream was mixed with 377g/h of pressurized water heated to a temperature so as to obtain asubstantially constant temperature of 350±5 C after mixing.

The mixed flow was subsequently contacted with the heterogeneouscatalyst in the reactor. The feed to water ratio translates into a waterto feed ratio of 3.75:1, and the total flow of 517 g/h translates into acontact time of 3.3 minutes.

After the contact with the heterogeneous catalyst, the fluid containingthe converted organic material was cooled to ambient temperature,filtered through a particle filter for collection of suspendedparticles, and expanded to ambient pressure. The liquid fraction on thestream is collected in a liquid trap, and the gas is vented off.

The experiment resulted in four product streams, a gas, an aqueousproduct, a free oil phase and a solid precipitate. Samples for analysiswas collected for a period of 16 hours.

Gas Analysis

The analysis of the gas phase revealed the following results:

Gas analysis Hydrogen [vol. %] 7.5 Carbon dioxide [vol. %] 88.74 Carbonmonoxide [vol. %] 0.00 Methane [vol. %] 0.33 Ethene [vol. %] 0.06 Ethane[vol. %] 0.06 Propene [vol. %] 0.25 Propane [vol. %] 0.05 C4-compounds[vol. %] 0.00 Total [vol. %]: Total amount of carbon, g 15.2Liquid Analysis

The analysis of the liquid phase revealed the following results:

Liquid analysis pH 8.30 Total Organic Carbon (TOC), [ppm by weight] 2105Total Inorganic Carbon (TIC), [ppm by weight] 201 Total Carbon, [ppm byweight] 2305 Methanol [vol %] 1.64 Ethanol [vol %] 0.27 Acetic acid [ppmby weight] 5185 Formic acid [ppm by weight] 2206 Glycol acid 10470Acetaldehyde [ppm by weight] 115.0 Total amount of carbon in liquid 40.1g

The inorganic carbon content in the liquid was found primarily to be dueto the presence of carbonate.

Solid Analysis

The solid fractions was analyzed by means of a total carbon analyzer. Anorganic phase was found to be adsorbed to the inorganic particles underthe experimental conditions used.

This organic phase was extracted prior to the solid analysis usingCH₂Cl_(2,). The extractable fraction of the organic carbon was found tobe an oil phase, primarily consisting of saturated hydrocarbons with achain length of 12 to 16 carbon atoms, and there for comparable to fuelor diesel oil. The oil contained phenol, toluene, 4-ethyl-phenol,4-ethyl-3-methylphenol, cyclopent-2-ene-1-one 2,3,4 trimethyl,2-methyl-1-penten-3-yne and other compounds. A sulphur analysis of theoil showed that the oil phase was essentially free of sulphur. A similaranalysis for halogen compounds showed that the oil phase was essentiallyfree of halogen. The total amount of oil extracted from the solids was14.76 g and the total amount of carbon found in the oil phase wasequivalent to 12.55 g.

No carbon was detected in the solid product after extraction of adsorbedoil, indicating 100% conversion of the organic material in the feed. Thesame result can be concluded from the carbon balance below:

Carbon Balance

Input C: Output C: Corn silage feed: 82.19 g 15.2 g gas C

18.5% 40.1 g TOC liquid

48.8% 0.0 TOC solid

0.0% 28.35 g C in oil

34.5% Σ 82.19 g Σ 83.62 g 101.8% conversion

Energy Balance

Heat Value Amount Energy Fraction Component [kJ/kg] [g] [% of feedenergy content] Feed sludge 476 2240 Hydrogen 240,103 0.07 1.6 Methanol19,918 28.9 17.9 Ethanol 28,200 4.20 4.2 Glycol acid 14,400 0.41 10.4Acetic acid 18,200 1.23 6.5 Oil 41,900 14.76 45.1 Sum 85.7

Additionally the following are definitions used in the description ofthe present invention.

The term hydrocarbon fuel is in the present invention intended to defineall hydrocarbon based fuels, which may or may not comprise otherelements than carbon and hydrogen, e.g. some of said hydrocarbons maycomprise oxygen and other elements e.g. in the form of groups ofalcohols, aldehydes, ketones, carboxylic acid, ester, esthers etc. andreaction products thereof.

The membrane processes of the present invention is well known in theprior art (e.g. W. S. HO et al, “Membrane Handbook”, Van NordstrandReinhold, p. 103-132, p. 263-446, 1992, ISBN 0-442-23747-2, K. Scott,“Handbook of Industrial Membranes” Elsevier Science Publishers, 1995, p.3-163, p. 331-355, p. 575-630, ISBN 1 85617 233 3)

The surface areas referred to throughout this specification and claimsare the nitrogen BET surface areas determined by the method described inthe article by Brunauer, P. Emmett and E. Teller, 3. Am. Chem. Soc.,Vol. 60, p. 309 (1938). This method depends on the condensation ofnitrogen into the pores, and is effective for measuring pores with porediameters in the range of 10 Å to 600 Å. The volume of nitrogen adsorbedis related to the surface area per unit weight of the support.

It is well known in the prior art that the activity of a catalyst isproportional to the surface area (BET), and that catalysts may show asignificant activity drop over time, when subjected to e.g. hydrothermalconditions as used in relation to the present invention. In order tominimize such potential activity loss a surface area stabilizer isincorporated into the heterogeneous catalyst.

Red Mud is a waste product of bauxite processing via the Bayer process.It comprises oxides and hydroxides of mainly aluminium, iron, titanium,silicon, and sodium.

1. A method for converting an organic material feed into a hydrocarbonfuel product, comprising the steps of: pressurizing said organicmaterial being in a slurry to a pressure above 225 bar, heating saidorganic material in said slurry to a temperature above 200° C. in thepresence of a homogeneous catalyst comprising a compound of at least oneelement of group IA of the periodic table of elements, wherein themethod further comprises the steps of: contacting said organic materialin said slurry with a heterogeneous catalyst in a reactor, theheterogeneous catalyst comprising a compound of at least one element ofgroup IVB of the periodic table and/or alpha-alumina assuring that saidslurry has initially a pH value of above 7, and maintaining the pH valueof said slurry containing said organic material in the range 7-14 and,re-circulating at least a part of the slurry exiting the reactor bymixing it into the slurry comprising organic material prior to thisentering the reactor, and wherein the concentration of said organicmaterial is at least 5% by weight, the conversion of said organicmaterial is at least 90%, and said hydrocarbon fuel product comprises anoil with at least 50% of the feed carbon content, pre-treating theslurry at a pressure of 4-15 bar at the temperature of 100-170° C. for aperiod of 0.5-2 hours, and wherein the step of pre-treating comprisesthe step of adding additives to the slurry comprising said organicmaterial, and wherein the step of pre-treating comprises the step ofadjusting the pH of said slurry comprising said organic material toabove
 7. 2. The method according to claim 1, wherein at least 50% of theenergy content in the feed is recovered in said hydrocarbon oil product.3. The method according to claim 1, further comprising a second step ofheating the slurry comprising the organic material before contacting theslurry with the heterogeneous catalyst.
 4. The method according to claim3, further comprising a step of separating fuel gas from the slurry,wherein the fuel gas is used for heating the slurry in the secondheating step.
 5. The method according to claim 1, further comprisingseparating particles from the slurry comprising the organic material. 6.The method according to claim 1, further comprising a first step ofcooling the slurry, performed by heat exchanging with the step ofheating and/or a step of pre-heating the slurry in the pre-treatingstep.
 7. The method according to claim 1, wherein the step of contactingthe organic material in the slurry with a heterogeneous catalyst isperformed while the temperature is kept substantially constant, andwherein the temperature in the step of contacting is in the range250-374 degrees Celsius, and wherein the pressure is in the range225-350 bars.
 8. The method according to claim 1, wherein the step ofcontacting is done in less than 10 minutes.
 9. The method according toclaim 1, wherein the compound of at least one element of group IVB ofthe periodic table comprises zirconium and/or titanium on an oxideand/or hydroxide form or a combination of the two.
 10. The methodaccording to claim 1, wherein the heterogeneous catalyst furthercomprises at least one element selected from the group consisting of Fe,Ni, Co, Cu, Cr, W, Mn, Mo, V, Sn, Zn, Si in an amount up to 20% byweight and wherein these elements are on an oxide and/or hydroxide form.11. The method according to claim 10, wherein said amount is up to 10%by weight, an amount up to 5% by weight, or an amount up to 2.5% byweight.
 12. The method according to claim 1, comprising the step ofre-circulating a slurry containing hydrogen, and wherein the hydrogencontent of said slurry corresponds to at least 0.001% by weight of theamount of said organic material to be treated.
 13. The method accordingto claim 1, wherein the homogeneous catalyst comprises potassium and/orsodium and wherein the homogeneous catalyst comprises one or more watersoluble salts selected from the group consisting of KOH, K₂CO₃, KHCO₃,NaOH, Na₂CO₃ or NaHCO₃ or a combination thereof, and wherein theconcentration of the homogeneous catalyst is at least 0.5% by weight.14. The method according to claim 1, wherein said slurry comprises waterin a concentration of at least 30% by weight.
 15. The method accordingto claim 1, wherein at least one carbonate and/or at least one hydrogencarbonate and/or at least one alcohol and/or at least one carboxylicacid and/or at least one aldehyde and/or at least one ketone is at leastpartly produced by the conversion of said organic material, and whereinsaid at least one carbonate and/or at least one hydrogen carbonateand/or at least one alcohol and/or at least one carboxylic acid and/orat least one aldehyde and/or at least one ketone is re-circulated afterthe step of contacting.
 16. The method according to claim 15, wherein atleast part of a stream of said re-circulation is mixed in a ratio with afeed stream of said slurry comprising said homogeneous catalyst andorganic material to be converted before entering the catalytic reactor.17. The method according to claim 16, wherein the ratio of there-circulating stream to the feed stream of said slurry is in the range1-20 by volume.
 18. The method according to claim 17, wherein the ratioof the re-circulating stream to the feed stream of said fluid is in therange 1-10, 1.5-7.5, 2-6, or 2.5-5 by volume.
 19. The method accordingto claim 1, wherein said organic material is selected from the groupconsisting of sludge, sewage sludge, liquid manure, corn silage,clarifier sludge, black liquor, residues from fermentation, residuesfrom juice production, residues from edible oil production, residuesfrom fruit and vegetable processing, residues from food and drinkproduction, leachate or seepage water or a combination thereof, andwherein said sludge is sludge from a biological treatment process. 20.The method according to claim 1, wherein said organic material is sludgefrom a waste water treatment process.
 21. The method according to claim1, wherein said organic material comprise a mixture of sludge,lidnocellulosic materials or waste.
 22. The method according to claim 1,wherein the recirculation comprises mixing at least a part of the slurryexiting the reactor into the slurry comprising organic material after orduring said pressurizing and heating of the slurry.
 23. The methodaccording to claim 22, wherein said heating is at least partly performedin a first heating unit, and wherein the at least a part of the slurryexiting the reactor is mixed into the slurry comprising organic materialat a point situated after said first heating unit in the feedingdirection.
 24. The method according to claim 1, wherein therecirculation comprises mixing at least a part of the slurry exiting thereactor into the slurry comprising organic material prior to thecompletion of said pressurizing and heating of the slurry.
 25. Themethod according to claim 24, wherein the at least a part of the slurryexiting the reactor is a fluid stream separated from the fluid exitingthe reactor in a product recovery system (11), and wherein the fluidstream is mixed into the slurry comprising organic material during apre-treatment of the organic material.